SDL: Check if touchpad exists before getting input

Verify a touchpad is present before polling it for input. Without this
check the Debug log is spammed with the message "error: Parameter
'touchpad' is invalid" if you have a controller without a touchpad.

One would think every touchpad supports at least 1 finger, but in case
there's some weird edge case check the finger count to be sure.

1 files changed, 9 insertions, 5 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/SDL/SDLGamepad.h b/Source/Core/InputCommon/ControllerInterface/SDL/SDLGamepad.h
index e71e3f4e52..4f03ea7d4a 100644
--- a/Source/Core/InputCommon/ControllerInterface/SDL/SDLGamepad.h
+++ b/Source/Core/InputCommon/ControllerInterface/SDL/SDLGamepad.h
@@ -362,11 +362,15 @@ public:
     const int touchpad_index = 0;
     const int finger_index = 0;
 
-    Uint8 state = 0;
-    SDL_GameControllerGetTouchpadFinger(m_gamecontroller, touchpad_index, finger_index, &state,
-                                        &m_touchpad_x, &m_touchpad_y, &m_touchpad_pressure);
-    m_touchpad_x = m_touchpad_x * 2 - 1;
-    m_touchpad_y = m_touchpad_y * 2 - 1;
+    if (SDL_GameControllerGetNumTouchpads(m_gamecontroller) > touchpad_index &&
+        SDL_GameControllerGetNumTouchpadFingers(m_gamecontroller, touchpad_index) > finger_index)
+    {
+      Uint8 state = 0;
+      SDL_GameControllerGetTouchpadFinger(m_gamecontroller, touchpad_index, finger_index, &state,
+                                          &m_touchpad_x, &m_touchpad_y, &m_touchpad_pressure);
+      m_touchpad_x = m_touchpad_x * 2 - 1;
+      m_touchpad_y = m_touchpad_y * 2 - 1;
+    }
 
     return Core::DeviceRemoval::Keep;
   }